How to differ "Sam from..." and "Sam is from..." whilst I see no auxiliary verb for the "being" part?
In Arabic we do not use the verb to be (am,is,are) in the present tense because it is considered implicitly understood. So it is translated as Sam [is] from America.
I'd need more of a description of what you're wanting to say.
There is no copula like "to be". Most likely for what you're asking the answer will be "Spell and pronounce it the same, and context will give it additional meaning."
It may be confusing at first, but once you actually speak a language without a copula it will be much easier. Similar to the differences in verb tenses from English to other languages. Like we say "I was walking" and "I walked" which in most languages will be said the exact same way. Esperanto for example uses "mi marŝis" for both.
These things seem the most confusing when theorizing and the least comfusing when in use